Graphdiyne oxide nanosheets reprogram immunosuppressive macrophage for cancer immunotherapy

Graphdiyne oxide (GDYO) nanosheets have remarkable electronic, mechanical, and thermal properties, which is hoped to act a better alternative for biomedical applications. Tumor-associated macrophage (TAM) is a promising cell population for nanotechnology application to cancer immunotherapy. In the present study, we found M2-like macrophages can be polarized to kill cancer cells with GDYO treatment via activation of pro-inflammatory pathways and GDYO injected intraperitoneally reduced tumor growth in a melanoma-bearing mouse model. In addition, GDYO activated cytotoxic T cells either directly or indirectly via macrophages, enhancing checkpoint inhibitor response in a breast cancer model. We expect that GDYO has invoked both the innate and adaptive arms of the immune system that are likely to enhance efficacy of cancer immunotherapy. [Display omitted] •GDYO-induced macrophage polarization was in a STAT3-TLR/MAPK forward feedback loop.•Anti-tumor effects of GDYO were consistent with the involvement of both macrophage and CD8+ T cell.•An effective strategy combining GDYO nanosheets with anti-PDL1 antibody boosting the efficacy of immunotherapy was proposed.